Barcodes are widely used as means for conveying various types of information. Barcodes in general are printed on paper media.
There is, however, an operational need for reading a barcode that is displayed on a screen of a terminal, instead of a barcode that is printed on a paper medium, with a barcode reading device (hereinafter also referred to as “barcode scanner” as necessary).
An example of the operational need is to provide some kind of service by displaying a barcode on a screen of a cellular phone or other terminal and by reading that barcode with the barcode scanner that is connected to a cash register or to a point of sales (POS) terminal at a shop or the like.
With a barcode displayed on a screen of a portable terminal in this manner, encoded information of the barcode can dynamically be changed and can be varied from one terminal displaying the barcode to another. In short, the barcode displayed on the screen of the portable terminal has a higher degree of freedom than that of a barcode printed on a paper medium. Further, displaying of the barcode on the screen of the portable terminal is expected to eliminate the trouble of printing the barcode and cut the cost of distribution.
When the barcode displayed on the screen of the portable terminal or the like is read with the barcode reading device, accurate reading of the displayed barcode naturally needs to be ensured each time. However, different portable terminal models have different specifications in terms of screen size, pixel counts in the longitudinal direction and the horizontal direction, and pixel density. Specifications also vary from one type of barcode scanner to another in terms of readable width and minimum resolution.
The resultant situation is that a barcode that can be read with the combination of one portable terminal model and one barcode scanner model cannot be read when a different portable terminal model and a different barcode scanner model are used in combination.
Technologies for preventing this situation are disclosed in, for example, Patent Document 1 and Patent Document 2.
In Patent Document 1, there are disclosed a barcode creating method for creating a barcode that can be displayed on a display of a mobile terminal and is readable with a barcode reading device, a barcode display device configured to display the barcode, and a barcode providing device configured to provide the barcode. The description of Patent Document 1 also includes taking into consideration the specifications of the display of the portable terminal on which the barcode is displayed, by varying the method of displaying the barcode from display to display.
In Patent Document 2, there is disclosed a barcode service providing system in which a table associating portable terminal model data and barcode image data with each other is prepared to display a barcode image that is associated with the portable terminal model of interest. In other words, taking into consideration the specifications of a display of the portable terminal on which the barcode is displayed, by varying the method of displaying the barcode from display to display, is included in Patent Document 2 as well.